Previously, we have presented preliminary studies examining the consistency and reliability of responses to the clinical health evaluation, selection bias as related to cardiovascular diseases, and comparability of healthy younger and older men when used for cross-sectional studies. During this reporting period, we completed these three studies. We found that BLSA participants answered questions in a consistent fashion over time and during the same visit, while physician asked questions were answered in a less consistent manner. Age of entry into a longitudinal study did not appear to cause an important amount of selection bias when considering cross sectional analysis of cardiovascular diseases. Cross sectional comparisons of healthy men at two ages overestimates the potential health status of the younger men when they become older. For example, comparing healthy 60 and 80 year old men, only 30% of the healthy 60 year old men will survive and remain healthy to age 80.